Do not get within visual range of a borgon vile lest their hailstorm of rocks damage you. Attack from afar. Borgon viles leave a trail of diamond needles that increase psionic ability if picked up.

Borgon Viles are arguably one of the most powerful creatures you can be polymorphed into through scrolls of wonder and other methods. The full screen area of effect innate power "Heat Radiation" kills outright many creatures, and severely damages powerful ones, and you retain the ability to wear armor and rings.